Tube bending pliers



O. SCHOPP TUBE BENDING PLIERS Filed Feb. 14, 1949 diys,

mhmwww Patented May 5, 1953 .BENDING 'PLIERS .Shoppa Ariz!! i George L.

snevof ene-half ,Anpiieetien February 14 19.49, Serial NO- 76.3.46

1 Claim. `(Ci..8 1-..-15)

This -invention relates to new and yuseful ini.- provmnis in a `hand-operatedtool for `bending tubes, rods, and the like at a given point to a predeterminedengle- An object of the invention is to provide a handoperated tool of the pliers type whereby a tube or rod can be bent to a predetermined angle without varying to any appreciable extent the cross sectional shape of the tube `or rodat the bend.

A further object of the invention is to provide a hand-operated bending tool of the above type wherein one of the jaws initially contacts the tube or rod at spaced Apoints and the other jaw initially contacts a tube or rod `at a point midway between said spaced points, and wherein each of said contacts between the jaws and the tube extends semi-circularly about the tube so thatv the bending forces are distributed and the tube can be bent to a relatively sharp angle without any appreciable cross-sectional deformation of the tube or rod.

In the drawings which show by illustration one embodiment of the invention,

Figure 1 is a perspective View of the bending tool with a tube therein bent by the tool to a 90 degree angle.

Figure 2 is a sectional view through the die forming heads of the tool in a plane which bisects the tube to be bent at the center thereof.

Figure 3 is a View similar to Figure 2 but showing the die heads closed and the tube bent to the desired angle.

Figure 4 is a sectional view on the line 4--4 of Figure 3.

Figure 5 is a sectional View on the line 5-5 of Figure 3.

The invention has to do With a hand-operated tool for bending tubes, rods, or the like, which is of the general type of construction as a pair of pliers. The tool includes handle members which are pivotally connected intermediate the inner and outer ends thereof. Each handle member at its inner end carries a die head. The opposed faces of these die heads are shaped so that one is the complement of the other. One of the die heads has the face thereof inwardlyshaped to conform to the desired angle to which the tube or rod is to be bent. The other die head has its inner face shaped so that when moved to closed position it will move inwardly into the first-named die head. The opposed faces of the die heads are grooved from one side to the other so that the groove is semi-circular in cross section and conforms to the cross section of the tube or rod to be bent. Alongside of the grooves each 2 die head has flat walls which -i'nove into Contact when the tube or rod is bent, thus limiting Vthe movement ofthe jaws andthus ypreventing any bending or collapsing of the tube.

Referring more in detail -to the drawings, the

vhand-operated bending tool includes a handle member Ihaving a die head 2 at the inner end thereof. It also includes a handle member 3 having a die head 4 at the inner end thereof. These vhandle members-are connected by a pivot 5 lo cated intermediate the ends of thehandle members. This bending ltool is of the natureof pliers vand the handle members are so shaped that when the handle members are pressed towards each other this will'close the die heads. The die head 4 at its inner face is shaped to conform to the angle to which the tube or rod is to be bent.

The inner face of the die head 4 is formed with straight portions 6, 6 which join each other at an angle which is curved as indicated at 1. This inner face of the die head 4 is provided with a groove 8 which extends from one side face of the die head to the other. This groove is semicircular in cross section and conforms to the semi-circular face of the tube or rod which is to be bent. The die head 2, at its inner face, is provided with straight portions 9 disposed at an angle to each other to conform to the angle of the straight portions 6 of the die head 4. These straight portions of the die head 2 meet at an angle which is slightly curved as indicated at I0. These at faces 9 of the die head 2, when the tool is closed as indicated in Figure l, will contact with the straight faces 6 of the die head 4. Said die head 2 is provided with a semi-circular groove II which extends from one side of the die head to the other, and when the die heads are closed, as shown in Fig. l, the grooves 8 and I I are opposed to each other and form a circular space conforming to the tube or rod `which is to be bent.

In the present embodiment of the invention, a tube T is shown placed in the bending tool when the die heads are separated one from the other. It is noted that the tube lies in the curved groove at opposite sides of the die head 4 as indicated at I2, I2. The tube also lies in the groove II at the inner portion thereof. The die head 4 will initially therefore contact with lthe tube throughout a semi-circular extent thereof. The same is true of the die head 2. It likewise makes a semi-circular contact with the tube. When the die heads are forced one toward the other for bending the tube, the forces which bend the tube are distributed over this semi-circular area vWhich is substantially a right angle.

t s of the tube and therefore the bending of the tube is accomplished Without any appreciable change in the shape of the tube at the bend.

When the tube has been bent to the desired angle, the flat faces 6 and 9 come into contact as lshown in Figures 4 and 5. This housing of the tube in the bend aids in the maintaining of the cross-sectional shape of the tube. In Figure 4 of the drawings which is a section on the line 4--4 through the bend in the tube, it is noted that the die heads 4 and 2 are in contact with the outer face of the tube throughout. It is 'also noted in Figure 5, Whichis a sec-- -tube at directly opposed points.

As shown in the drawings, these die shaping faces of the die heads are formed on an angle It Will be understood, however, that the angle may be an obtuse angle, or the die faces, instead of being angular, may be curved so that a tube may be curved or may be bent at an angle, and in either case the bend in the tube is brought about Without any appreciable change in the cross section of the tube.

While the die shaping heads are shown as formed integral. with the handle members, it will be understood that these heads may be detachable for the purpose of'substituting die shaping heads with the opposed faces thereof shaped so as to provide other angular bends in the tube as referred to above.

I claim:

A tool for formingr angular bends in tubes comprising die heads and means for supporting and moving said die heads toward and from each other, said die heads having complemental tube engaging faces each including straight portions disposed in the same angular relation to each other to which the tube is to -be bent, said straight portions being grooved `and joined midway of the die faces by a grooved curved section `and said straight grooves and said joining groove lbeing semi-circular in cross section and dimensioned so as to contact the tube throughout a semi-circular area and thus distribute the bending forces applied to the tube so that the bending of the tube is accomplished without any appreciable change in the cross-sectional shape of the tube at the bend.

OTTO SCI-IOPP.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 371,639 Taylor Oct. 18, 1887 2,253,906 Lehman Aug. 26, 1941 2,477,727 Engberg Aug. 2, 1949 FOREIGN PATENTS Number Country Date 44,706 Switzerland May 5, 1909 

